In recent years, advanced IT application such as introduction of electronic charts is widely seen in the medical industry for the purpose of increasing the efficiency of data management and processing. Because the number of days of a patient's stay in a hospital tends to decrease, increasing attention is being focused on home nursing. Advanced IT enables a home visiting nurse for home nursing to record personal information for a great number of patients all at once into an information processing terminal, and to carry it with the home visiting nurse. On the other hand, in the case where the information processing terminal is stolen during the visit, a problem of disclosure of privacy arises.
As a technique for protecting privacy, there is a technique (for example, see Patent Literature 1), in which the information recorded in the information processing terminal is encrypted, while access control is performed with the location information and temporal information obtained by GPS (Global Positioning System).
In addition, techniques for performing access control using location information includes another technique (for example, see Patent Literature 2), in which information is encrypted using the location information obtained from a GPS as a key.